Cutting apparatus

ABSTRACT

A cutting apparatus including a pair of blades respectively having linearly extending cutting edges so that the cutting edges are brought into sliding contact with each other to cut a member to be cut which is put between the cutting edges. The cutting apparatus is provided with press members for bringing the sliding contact surface of one of the cutting edges into press contact with the sliding contact surface of the other when the two blades are brought into sliding contact with each other, the press members being disposed along one of the blades. Thus, the sliding contact between the two blades is ensured independently of the rigidity of the blades. Accordingly, it becomes possible to reduce the thickness and increase the length of the blades.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cutting apparatus.

2. Description of the Related Art

Cutting apparatuses of the type in which the cutting edges of a pair oflinear blades are brought into sliding contact with each other to cut asheet-like member, for example, paper, film, etc., put between thecutting edges have already been known. However, there have recently beenincreasing demands also for this type of cutting apparatus to decreasein weight and size and increase in the cutting speed.

More specifically, in cutting apparatuses used in plotters, printers,etc. to cut an exceedingly wide sheet-like member in the widthwisedirection, a pair of stationary and moving blades which are incontinuous form are employed and there is a tendency for the weight ofthe moving blade to increase more and more in proportion to the length.As the weight of the blade increases, however, it becomes difficult tocontrol the high-speed movement of the blade and the cutting speedinevitably lowers.

If the thickness of the moving blade is reduced in order to reduce theweight, the rigidity lowers, so that, when the moving blade comes intosliding contact with the stationary blade, the cutting edge of themoving blade may bend and deflect from the cutting edge of thestationary blade due to the cut resistance, resulting in a gap beinggenerated between the two blades, and thus causing a cutting failure.

SUMMARY OF THE INVENTION

In view of the above-described problems of the prior art, it is aprimary object of the present invention to provide a cutting apparatuswhich is capable of ensuring the sliding contact between the two bladeseven if the blade rigidity is low, thereby reducing the blade weight,and thus achieving an increase in the speed of movement of the movingblade.

To this end, the present invention provides a cutting apparatusincluding a pair of blades respectively having linearly extendingcutting edges so that the cutting edges are brought into sliding contactwith each other to cut a member to be cut which is put between thecutting edges, wherein the improvement comprises press means forbringing the sliding contact surface of one of the cutting edges intopress contact with the sliding contact surface of the other when the twoblades are brought into sliding contact with each other, the press meansbeing disposed along the blade.

In the cutting apparatus having the above-described arrangement, thesliding contact surfaces of the pair of blades are brought into presscontact with each other by the press means and consequently the slidingcontact between the two blades is ensured independently of the rigidityof the blades. Accordingly, it becomes possible to reduce the thicknessand increase the length of the blades.

The above and other objects, features and advantages of the presentinvention will become more apparent from the following description ofthe preferred embodiments thereof, taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 9 show in combination a first embodiment of the presentinvention, in which:

FIG. 1 is a front view of a cutting apparatus;

FIG. 2 is an enlarged view showing the cutting apparatus with the middleportion thereof omitted;

FIGS. 3(a) and 3(b) are enlarged views each showing a combination of apin and an elongated hole;

FIG. 4 is a sectional view showing a pin and an elongated holeassociated therewith;

FIG. 5 is a perspective view showing a moving blade, stationary bladeand press member;

FIGS. 6(a) and 6(b) are vertical sectional views showing the two blades;and

FIGS. 7, 8 and 9 are sectional views respectively showing modificationsof the press member or press means.

FIGS. 10 to 12 show in combination a second embodiment of the presentinvention, in which:

FIG. 10 is a perspective view of a paper cutter;

FIG. 11 is a vertical sectional view showing the blades and associatedmembers of the paper cutter; and

FIG. 12 shows a modification of the press member.

FIGS. 13 to 15 show in combination a third embodiment of the presentinvention, in which:

FIG. 13 is a schematic vertical sectional view of a paper cutter; and

FIGS. 14 and 15 are perspective views of the paper cutter.

FIG. 16 is a plan view of a paper cutter according to a fourthembodiment of the present invention.

FIGS. 17 to 21 show in combination a fifth embodiment of the presentinvention, in which:

FIG. 17 is a perspective view of a pair of scissors;

FIG. 18 is a perspective view showing the way in which a press member isattached to one blade of the scissors;

FIG. 19 is a vertical sectional view of the pair of blades of thescissors; and

FIGS. 20(a), 20(b), 21(a) and 21(b) are vertical sectional views similarto FIG. 19, which respectively show modifications of the press member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described below in more detail by way ofembodiments and with reference to the accompanying drawings.

First Embodiment

FIG. 1 is a front view of a cutting apparatus 10 according to a firstembodiment of the present invention. In the figure, the referencenumeral 12 denotes a support plate that extends horizontally. A pair ofstationary blade 14 and moving blade 16 are attached to the supportplate 12 along the lower and upper parts, respectively, of the supportplate 12. Each of the blades 14 and 16 is formed in a continuous lengthfrom a thin steel plate, and cutting edges 14a and 16a are formed alongthe respective longitudinal edges of the blades 14 and 16 in opposingrelation to each other, as is clearly shown in FIG. 2.

The moving blade 16 is attached to the support plate 12 in the mannerdescribed below. As shown in FIGS. 2 to 4, pins 18 and 20 are providedon one side of the moving blade 16 at two longitudinal end portions,respectively, the pins 18 and 20 being formed as integral parts of theblade 16. The pins 18 and 20 are loosely fitted in respective slantguide holes 22 and 24 which are formed in the support plate 12.Accordingly, when moved sideward, the moving blade 16 is caused to movevertically by the action of the guide holes 22 and 24. The drive of themoving blade 16 is effected by a solenoid-operated actuator 26 which isdisposed at one end of the support plate 12. The actuating shaft 26a ofthe actuator 26 has an elongated connecting hole 28 formed in the distalend portion thereof, as shown in FIG. 2, and a connecting pin 30 that isintegrally provided on one side of the moving blade 16 and at the endthereof which is closer to the actuator 26 is loosely fitted in theconnecting hole 28. At the other end of the support plate 12 is disposedan extension spring 32 which is retained at one end by a retaining hole34 in the support plate 12 and at the other end by a retaining hole 36in the moving blade 16. Accordingly, the moving blade 16 is constantlybiased rightward as viewed in FIG. 2, and when the actuator 26 is turnedon, the moving blade 16 moves downward while being pulled leftward, asshown by the chain line in FIG. 2, whereas, when the actuator 26 isturned off, the moving blade 16 moves upward while being pulledrightward by the extension spring 32.

On the other hand, the stationary blade 14 is fixed to the support plate12 at a predetermined angle so that the moving blade 16 comes intosliding contact with the stationary blade 14 at an angle, as shown inFIGS. 5 and 6. It should be noted that the stationary blade 14 is,although not clearly shown, rigidly secured to the support plate 12 overthe entire length thereof so that it will not be deformed although theplate thickness thereof is relatively small.

In regard to the guide holes 22 and 24 in the support plate 12, morespecifically, the right-hand (as viewed in FIG. 2) guide hole 24 slantsmore steeply than the left-hand guide hole 22 so that the moving blade16 comes into sliding contact with the stationary blade 14 at apredetermined angle from the right-hand portion to the left-hand portionthereof.

A plurality of press members 38 are disposed at predetermined distancesalong the side of the support plate 12 which faces the sliding contactsurface 14b of the cutting edge 14a of the stationary blade 14. Eachpress member 38 comprises a rotatable elongated press roller 40 and aresilient bracket plate 42. The shaft 44 of the roller 40 is supportedby projections 42a provided at both ends, respectively, of the distalend portion of the bracket plate 42. The lower part of the bracket plate42 is secured to the support plate 12 by means of screws 46. The gapbetween the roller 40 and the stationary blade 14 is set so as to beslightly smaller than the plate thickness of the moving blade 16 in anormal state so that, when the cutting edge 16a of the moving blade 16is inserted into the gap, the bracket plate 42 is resiliently deflecteda little backward.

The press members 38, or press means, may be modified as shown in FIGS.7, 8 and 9. The modification shown in FIG. 7 is arranged such that thestationary blade 14 and a press member 48 are formed integral with eachother from the same member and the gap between the press member 48 andthe stationary blade 14 can be adjusted by means of an adjusting screw50. Since no roller is used, the frictional resistance to the movingblade may be greater than in the case of the first embodiment. However,this modification can be carried out at reduced cost because thestructure is relatively simple. In the modification shown in FIG. 8, thestationary blade 14 and a press member 52 are formed from separatemembers, but these members are connected together in one unit by meansof a rivet 54 with a view to setting the above-mentioned gap with highaccuracy and facilitating mounting of these members to the support plate12. In the modification shown in FIG. 9, the respective sliding contactsurfaces 14b, 16b of the pair of cutting edges are brought into presscontact with each other by means of magnetic force instead of themechanical pressing force. More specifically, in this modification, themoving blade 16 is magnetized so that the front side (hatched side) ofthe moving blade 16 functions as the north pole and the other sidethereof as the south pole, and the distal end portion of the stationaryblade 14 which is brought into sliding contact with the moving blade 16is magnetized so as to be the south pole. These magnetic polarities may,of course, be interchanged with each other.

In the above-described cutting apparatus 10, a sheet-like member 56 isdelivered in the direction of the arrow through the area between thestationary blade 14 and the moving blade 16, as shown in FIG. 6(a).After the sheet-like member 56 has been delivered to a predeterminedlength, the solenoid-operated actuator 26 is turned on. In consequence,the moving blade 16 is pulled leftward as viewed in FIG. 2 by theactuating shaft 26a of the actuator 26. The cutting edge 16a of themoving blade 16 begins to come into sliding contact with the stationaryblade 14 at a predetermined angle from the right-hand side thereof dueto the difference in the gradient between the guide holes 22 and 24, andthe sliding contact portion shifts successively to the left from it.When the moving blade 16 has come into sliding contact with thestationary blade 14 over the entire width thereof, cutting of thesheet-like member 56 is completed. During this cutting process, theabove-mentioned cutting angle is maintained substantially at a constantlevel.

As shown in FIG. 6(b), at the same time as the cutting edge 16a of themoving blade 16 comes into sliding contact with the cutting edge 14a ofthe stationary blade 14, the press rollers 40 resiliently press the backsurface 16c of the moving blade 16. Accordingly, even when the rigidityof the moving blade 16 is lower than in the case of the prior artbecause the blade 16 is thin, the moving blade 16 is prevented fromdeflecting rightward as viewed in FIG. 6(b), which would otherwise occurdue to the cut resistance of the sheet-like member 56, thus enabling aneffective cutting condition to be maintained. It should be noted thatsince the rollers 40 rotate when the moving blade 16 moves up and down,the resistance to the movement of the moving blade 16 has substantiallyno increase as compared with the prior art.

Second Embodiment

FIGS. 10 to 12 show in combination a second embodiment in which thepresent invention is applied to a paper cutter. The paper cutter 80 ofthis embodiment has press members 86 which are additionally attached tothe base plate 82 of an ordinary paper cutter at respective positionsnear the stationary blade 84. More specifically, a plurality of pressmembers 86 each formed from a substantially L-shaped member are disposedat predetermined distances along the longitudinal axis of the stationaryblade 84. The lower end portion 86a of each press member 86 is securedto the lower side of the base plate 82 by means of screws 88, while theupper end portion 86b thereof is extended so as to face the slidingcontact surface of the cutting edge of the stationary blade 84 across apredetermined gap.

When the handle 90 of the paper cutter 80 is pushed down to cut paper(not shown), the back surface 92c of the moving blade 92 is pressed bythe upper end portions 86b of the press members 86, thus preventing themoving blade 92 from deflecting laterally outside from the stationaryblade 84. Accordingly, excellent cutting can be effected without theneed to specially apply inward force to the handle 90.

It should be noted that, if rollers are desired to be used for the pressmembers, a roller 96 may be rotatably supported at the distal end ofeach press member 94 formed from wire, as shown in FIG. 12. With thisarrangement, press members comprising rollers can be realized withrelative ease and at relatively low cost.

Third Embodiment

FIGS. 13 to 15 show in combination a third embodiment of the presentinvention, in which a moving blade is attracted toward a stationaryblade by means of an electromagnet. Referring to FIG. 13, which is aschematic vertical sectional view of the paper cutter, a moving blade 98which is formed into a permanent magnet is attached to an elevatingsupport member 100 and a plate 102 made of permanent magnet is disposedalong the vertical path of movement of the moving blade 98. The movingblade 98 and the elevating support member 100 are of extended length inthe direction perpendicular to the plane of the drawing, and theextending end portion of the elevating support member 100 is connectedto a driving means (not shown) so as to be driven to move up and down.The plate 102 and the moving blade 98 have their opposing surfaces madedifferent from each other in magnetic polarity so that these opposingsurfaces attract each other by magnetic force. For example, the opposingsurfaces of the plate 102 and the moving blade 98 are defined as thenorth and south poles, respectively. The elevating support member 100 isprovided with a roller 104 which rolls along the surface of the plate102. The roller 104 maintains a predetermined gap between the movingblade 98 and the plate 102. If the arrangement is such that the amountby which the roller 104 projects from the moving blade 98 can beadjusted, it is possible to adjust the above-mentioned gap.

The foregoing paper cutter may also be arranged such that, instead ofusing the permanent magnet plate 102, a plate 102 that is not magnetizedis used as a mere guide plate and an electromagnet 108 is newly disposedsubstantially horizontally at a position somewhat above the stationaryblade 106, thereby attracting the moving blade 98 toward the stationaryblade 106. In this case, if the coil 108 is energized to attract themoving blade 98 toward the stationary blade 106 only for the moment whenthe former comes into sliding contact with the latter, the power neededto drive the moving blade 98 can be minimized. The ON/OFF switching ofthe current circuit supplying current to the coil 108 may be effected bya switch 124 which opens and closes in association with the movement ofthe elevating support member 100.

FIG. 14 shows a modification which is the same as that shown in FIG. 13except that it uses no elevating support member. The moving blade, themagnetic plate and the stationary blade are denoted by the samereference numerals as those in FIG. 13. FIG. 15 shows a hand operatedpaper cutter which uses the same principle as that in the arrangementshown in FIG. 13. In FIG. 15, the moving blade, the magnetic plate andthe stationary blade are denoted by the reference numerals 110, 112 and114, respectively.

It should be noted that, instead of using the magnetic plate, a solenoidcoil may be buried in the stationary blade to magnetize the stationaryblade itself at the time of cutting.

Fourth Embodiment

FIG. 16 is a schematic plan view of a cutting apparatus which enables asheet-like member to be cut along any desired curve. In the figure, thereference numeral 120 denotes a moving blade in continuous thin plateform, which is driven to move up and down by a driving means (not shown)in the direction perpendicular to the plane of the drawing. The movingblade 120 is bent so as to coincide with a desired cutting curve, and aplurality of rollers 122 which serve as press members are disposed atone side of the moving blade 120 and along the longotudinal axis thereofso that, when the moving blade 120 comes into sliding contact with thestationary blade, the former is prevented from laterally deflecting fromthe latter by means of the rollers 122. It should be noted thatillustration of the stationary blade is omitted in the figure.

This cutting apparatus realizes an epoch-making advantageous effect thata sheet-like member can be cut into a desired length along a desiredcurve including a circularly curved line, S-shaped line, etc. As pressmembers, it is possible to adopt those which employ no rollers or thosewhich utilize magnetic force produced from a permanent magnet and/or anelectromagnet, in addition to the above-described press memberscomprising rollers.

Fifth Embodiment

FIGS. 17 to 21 show in combination an embodiment in which the presentinvention is applied to a pair of scissors. These scissors 130 aredifferent from ordinary scissors in that press members 134 are attachedto one blade 132, as shown in FIG. 17. As specifically shown in FIG. 18,each press member 134 comprises two press portions 134a which areconnected together through a connecting portion 134b. An L-shaped bentportion 134c which is bent inward is formed at the upper end of theconnecting portion 134b, as shown in FIG. 19, and a groove 138 which iscapable of receiving the bent portion 134c is formed in the outersurface of the blade 132. Accordingly, simply by inserting the blade 132into a groove 136 defined between the press portions 134a and connectingportion 134b of the press member 134, the bent portion 134c and thegroove 138 engage with each other and thus the press member 134 can beattached effectively and reliably. On the blade 132 are disposed twopress members 134 and hence four press portions 134a. The press portions134a are disposed so as to face the inner sliding contact surface 132bof the cutting edge 132a of the blade 132 so that, when the other blade140 comes into sliding contact with the blade 132, the press portions134a press the back surface 140c of the blade 140.

FIG. 20(a) shows a modification in which a press member 142 and a blade144 are formed integral with each other, and FIG. 20(b) shows amodification in which a roller 148 is attached to the distal end of apress member 146 formed from wire attached to blade 149.

FIG. 21(a) shows a modification in which the inner sliding contactsurfaces of a pair of blades 150 and 152 are magnetized so as to bedifferent from each other in magnetic polarity, and FIG. 21(b) shows amodification in which a permanent magnets 156, 156' and/blades 158, 158'are buried in one unit in each of two support members 154, 154' made ofa resin material. In these modifications, the pair of blades areattracted to each other by magnetic force and therefore prevented frommoving away from each other when cutting an object to be cut.

Thus, according to the present invention, the sliding contact surfacesof a pair of blades of a cutting apparatus are brought into presscontact with each other by press means. Accordingly, even if therigidity of the blades is low, generation of a gap between the blades isprevented. It is therefore possible to reduce the thickness and weightof the blades, increase the length thereof and lower the production costand, as a result of the reduction in the weight, it becomes possible todrive the moving blade at high speed.

Although the present invention has been described through specificterms, it should be noted here that the described embodiments are notnecessarily exclusive and that various changes and modifications may beimparted thereto without departing from the scope of the invention whichis limited solely by the appended claims.

What is claimed is:
 1. A cutting apparatus including a pair of co-actingblades respectively having linearly extending cutting edges so that saidcutting edges are brought into sliding contact with each other andcreate a sliding contact surface on each of said cutting edges, whereinsaid pair of blades comprise a first stationary blade and a secondmoving blade which are of continuous thin plate form, at least saidsecond moving blade being formed from a magnetic material, and saidsecond moving blade being adapted for movement in a first direction forsliding contact of the sliding contact surface of said second movingblade with the sliding contact surface of said first stationary blade,said cutting apparatus further comprising means arranged along at leasta substantial segment of said first stationary blade for drawing thecutting edge of said second moving blade in a second direction,generally transverse to said first direction, toward the cutting edge ofsaid stationary blade by means of magnetic force when said slidingcontact surface of the cutting edge of said second moving blade comesinto sliding contact with said sliding contact surface of the cuttingedge of said first stationary blade, thereby drawing said slidingcontact surface of the cutting edge of said second moving blade togetherwith said sliding contact surface of the cutting edge of said firststationary blade.